Vehicle systems and methods with improved heating performance

ABSTRACT

A vehicle system includes an electric motor, an internal combustion engine, and a heating system configured to transfer heat from the internal combustion engine to a passenger compartment of the vehicle. The system includes a controller configured to operate the electric motor and the internal combustion engine according to one of a plurality of drive cycle profiles. The controller selects the drive cycle profile based on an ambient temperature. The drive cycle profiles include a first drive cycle profile that commands power from the electric motor until the battery system reaches a predetermined state of charge and subsequently commands power from the internal combustion engine and a second drive cycle profile that commands power from the internal combustion engine and subsequently commands power from the electric motor.

TECHNICAL FIELD

The present invention generally relates to vehicle systems and methods,and more particularly relates to vehicle systems and methods withimproved heating performance.

BACKGROUND

In recent years, advances in technology have led to substantial changesin the design of automobiles. One of the changes involves the complexityof the electrical systems within automobiles, particularly alternativefuel vehicles, such as hybrid, battery electric, and fuel cell vehicles.Such alternative fuel vehicles may use one or more electric motors incombination with internal combustion engines to drive the wheels. Withfluctuations in fossil fuel prices, it is now more desirable than everto power automobiles with the electric power of the electric motor.

Generally, heating systems in vehicles rely upon heat from the internalcombustion engine to provide heat to the passenger compartment. Thisbecomes an issue at low temperatures during operation with the electricmotor. However, as noted above, it is generally desirable from a fuelperspective to operate the vehicle with the electric motor. As a resultof this arrangement, operator comfort may be compromised at lowertemperatures until the battery power of the electric motor is depletedand internal combustion engine operation is initiated.

Accordingly, it is desirable to provide vehicle systems and methods withimproved heating performance, particularly in vehicles that use aninternal combustion engine and an electric motor. Furthermore, otherdesirable features and characteristics of the present invention willbecome apparent from the subsequent detailed description of theinvention and the appended claims, taken in conjunction with theaccompanying drawings and this background of the invention.

BRIEF SUMMARY

In accordance with an exemplary embodiment, a system for a vehicleincludes a battery system and an electric motor coupled to the batterysystem and configured to selectively provide power to the vehicle withenergy from the battery system. The system further includes an internalcombustion engine configured to selectively provide power to the vehicleand a heating system configured to transfer heat from the internalcombustion engine to a passenger compartment of the vehicle. The systemincludes a controller configured to operate the electric motor and theinternal combustion engine according to one of a plurality of drivecycle profiles. The controller selects the drive cycle profile based onan ambient temperature. The drive cycle profiles include a first drivecycle profile that commands power from the electric motor until thebattery system reaches a predetermined state of charge and subsequentlycommands power from the internal combustion engine and a second drivecycle profile that commands power from the internal combustion engineand subsequently commands power from the electric motor.

In accordance with another exemplary embodiment, a method is provide foroperating a vehicle with an electric motor that provides power to thevehicle with energy from the battery system, an internal combustionengine, and a heating system that transfers heat from the internalcombustion engine to a passenger compartment of the vehicle. The methodincludes receiving an initial location and an intended destination;generating a trip profile for a trip between the initial location andthe intended destination; receiving, by a controller, an ambienttemperature; selecting, by the controller, a drive cycle profile from aplurality of drive cycle profiles based on the trip profile and theambient temperature; and operating the vehicle according to the selecteddrive cycle profile. The drive cycle profiles include a first drivecycle profile that commands power from the electric motor until thebattery system reaches a predetermined state of charge and subsequentlycommands power from the internal combustion engine and a second drivecycle profile that commands power from the internal combustion engineand subsequently commands power from the electric motor.

In a further exemplary embodiment, a heating performance system isprovided for a vehicle with an electric motor and an internal combustionengine. The heating performance system includes a trip module configuredto generate a trip profile for a trip between an initial location and anintended destination; a drive cycle module coupled to the trip moduleand configured to generate at least a first drive cycle profile and asecond drive cycle profile based on the trip profile; and a controllercoupled to the drive cycle module and configured to select between thefirst drive cycle profile and the second drive cycle profile based on anambient temperature for operation of the vehicle according to theselected drive cycle profile. The first drive cycle profile commandspropulsion power from the internal combustion engine at a first positionduring the trip profile and the second drive cycle profile commandspropulsion power from the internal combustion engine at a secondposition during the trip profile, earlier than the first position. Thecontroller is configured to select the second drive cycle profile whenthe ambient temperature is less than a predetermined temperature suchthat heat from the internal combustion engine is directed into apassenger compartment of the vehicle earlier in the trip profile.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will hereinafter be described in conjunction withthe following drawing figures, wherein like numerals denote likeelements, and

FIG. 1 is a schematic block diagram of a vehicle with a heatingperformance system in accordance with an exemplary embodiment;

FIG. 2 is a trip profile associated with the vehicle of FIG. 1 inaccordance with an exemplary embodiment;

FIG. 3 is a first chart of energy usage of the vehicle of FIG. 1 inaccordance with an exemplary embodiment;

FIG. 4 is a second chart of energy usage of the vehicle of FIG. 1 inaccordance with an exemplary embodiment; and

FIG. 5 is a flowchart of a method for improving heating performance inaccordance with an exemplary embodiment.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the invention or the application and uses of theinvention. As used herein, the word “exemplary” means “serving as anexample, instance, or illustration.” Thus, any embodiment describedherein as “exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments. All of the embodiments describedherein are exemplary embodiments provided to enable persons skilled inthe art to make or use the invention and not to limit the scope of theinvention which is defined by the claims. Furthermore, there is nointention to be bound by any expressed or implied theory presented inthe preceding technical field, background, brief summary, or thefollowing detailed description.

The following description refers to elements or features being“connected” or “coupled” together. As used herein, “connected” may referto one element/feature being mechanically joined to (or directlycommunicating with) another element/feature, and not necessarilydirectly. Likewise, “coupled” may refer to one element/feature beingdirectly or indirectly joined to (or directly or indirectlycommunicating with) another element/feature, and not necessarilymechanically. However, it should be understood that although twoelements may be described below, in one embodiment, as being“connected,” in alternative embodiments similar elements may be“coupled,” and vice versa. Thus, although the schematic diagrams shownherein depict example arrangements of elements, additional interveningelements, devices, features, or components may be present in an actualembodiment.

FIG. 1 is a schematic block diagram of a vehicle (or automobile) 100 inaccordance with an exemplary embodiment. The vehicle 100 includes achassis 102, a body 104, four wheels 106 (although other embodiments mayhave two or three wheels), and an electronic control system (ECU) 108.The body 104 is arranged on the chassis 102 and substantially enclosesthe other components of the vehicle 100. The body 104 and the chassis102 may jointly form a frame. The wheels 106 are each rotationallycoupled to the chassis 102 near a respective corner of the body 104.

The vehicle 100 may be any one of a number of different types ofautomobiles, such as, for example, a sedan, a wagon, a truck, or a sportutility vehicle (SUV), and may be two-wheel drive (2WD) (i.e.,rear-wheel drive or front-wheel drive), four-wheel drive (4WD), orall-wheel drive (AWD). As described below, the vehicle 100 may alsoincorporate any combination of a number of different types of enginesand motors, and the vehicle 100 shown in FIG. 1 and described herein ismerely intended as one example. It should be noted that exemplaryembodiments discussed herein are applicable to other types of landvehicles, such as motorcycles and personal transportation devices, aswell as other categories of vehicles, such as watercraft and aircraft.

In the exemplary embodiment illustrated in FIG. 1, the vehicle 100includes an actuator assembly 120, a battery system (or battery) 122, apower converter assembly (e.g., an inverter assembly) 124, and a batterycharge port 126. The actuator assembly 120 includes an internalcombustion engine 132 and an electric motor (or motor/generator) 134. Asdescribed below, the internal combustion engine 132 and the electricmotor 134 may be selectively operated to produce power for the wheels106 via the drive shafts 136.

The internal combustion engine 132 may be a liquid or gas fueledinternal combustion engine. Examples of fuels that may be used includegasoline, diesel, “flex fuel” (e.g., a mixture of gasoline and alcohol),methanol, methyl tetrahydrofuran mixtures, various biodiesels, andliquefied petroleum gas (LPG).

The electric motor 134 may be any type of motor that functions togenerate mechanical power from the energy stored in the battery system122. Typically, the electric motor 134 includes a transmission therein,and although not illustrated, also includes a stator assembly (includingconductive coils), a rotor assembly (including a ferromagnetic core),and a cooling fluid. The battery system 122 may include any suitabledirect current (DC) power supply or electrical energy storage devicesource, including a 12V, lead-acid starter-lighting-ignition (SLI)battery and/or a lithium ion battery. Although not shown in detail, inone embodiment, the power converter assembly 124 includes a three-phasecircuit coupled to the electric motor 134 to selectively drive the motor134.

The electronic control system (ECU) 108 is in operable communicationwith the actuator assembly 120, the battery system 122, the powerconverter assembly 124, and the charge port 126. Although not shown indetail, the ECU 108 includes various sensors and automotive controlmodules, or electronic control sub-units or modules (ECMs), such as aninverter control module and a vehicle controller, and at least oneprocessor and/or a memory which may include instructions stored thereon(or in another computer-readable medium) for carrying out the functionsdescribed herein.

As noted above, either the electric motor 134 and/or the internalcombustion engine 132 generate power to operate the vehicle 100. Duringoperation, the ECU 108 may operate the actuator assembly 120 with anyrelative combination of contributions from the internal combustionengine 132 and electric motor 134. The combination of relative operationmay be referenced below as a drive cycle, and the ECU 108 may store,generate, or receive drive cycle profiles associated with the drivecycles to operate the actuator system 120 in various situations, asdescribed in greater detail below. Accordingly, the ECU 108 may generatedrive cycle commands to selectively operate the internal combustionengine 132, motor 134, and associated systems. Generally, the vehicle100 is an extended range electric vehicle (EREV), although in otherembodiments, the vehicle 100 may be considered a plug-in hybrid electricvehicle (PHEV).

Due to emissions standards, consumer preference, and/or otherincentives, it is generally desirable to operate with the electric motor134 to the extent possible or feasible, e.g., such that the electricmotor 134 is the sole mechanism for propelling the vehicle and theengine 132 does not operate. As a result, during typical operation, theECU 108 operates the actuator system 120 according to a drive cycleprofile in which the vehicle 100 is powered by the electric motor 134until the energy in the battery system 122 is depleted (or has otherwisereached a predetermined minimum state of charge), at which time theinternal combustion engine 132 is started to power the vehicle 100. Attimes, the vehicle 100 will reach the intended destination prior todepletion of the battery system 122 such that the internal combustionengine 132 is not used. In other situations, the internal combustionengine 132 is only utilized at the very end of a trip. As discussedbelow, the ECU 108 may receive commands from a heating performancesystem 160 to operate according to an alternative or modified the drivecycle profile as compared to the typical profiles described above.

The vehicle 100 may further include a heating system 140 for providingwarm air to the interior or passenger compartment of the vehicle. As isgenerally understood, the heating system 140 typically uses one or morefluid circuits to transfer heat generated by the internal combustionengine 132 into the passenger area, e.g., based on passenger or drivercommands via a console. Considering that the vehicle 100 may be a hybridvehicle in which the internal combustion engine 132 is not operated atall times, the heating system 140 may further include a positive thermalcoefficient (PTC) heater 142. The PTC heater 142 includes a heatingelement that is powered by the battery system 122 such that the heatingsystem 140 may operate when the internal combustion engine 132 is notoperating. In one exemplary embodiment, heat from the PTC heater 142 maynot be as effective in generating heat as compared to the internalcombustion engine 132. In other embodiments, the PTC heater 142 may beomitted.

The vehicle 100 may include any number of sensors to measure orotherwise derive various parameters. The sensors may include, asexamples, an ambient sensor 150, an engine sensor 152, and a batterysensor 154. The ambient sensor 150 generally functions to determine theambient or atmospheric temperature outside the vehicle and/or inside thepassenger compartment. The engine sensor 152 generally functions todetermine the temperature of the internal combustion engine 132. Thebattery sensor 154 generally functions to determine the charge of thebattery system 122.

As will now be introduced, the heating performance system 160 generallyfunctions to modify operation of the vehicle 100 to improve the heatingperformance, particularly with respect to heating the passengercompartment of the vehicle for operator comfort. In one exemplaryembodiment, the heating performance system 160 may estimate a “warmingenergy” that represents the energy necessary to warm the passengercompartment to a predetermined temperature that may be set by the userand/or manufacturer. The warming energy estimation may be based on anumber of factors, including the ambient temperature and operatingcharacteristics of the driver, the heating system 140, the engine 132,and the electric motor 134. The heating performance system 160 may alsofunction to heat designated components. As such, in further embodiments,the heating performance system 160 may estimate the energy necessary towarm these components. Additional details about these functions will beprovided below.

Generally, the heating performance system 160 includes a user interface162, a navigation module 164, and a controller 170 with a trip profilemodule 172 and a drive cycle module 174. Although shown in FIG. 1 asbeing arranged on the vehicle 100, one or more of the components of theheating performance system 160 may be located off the vehicle 100. Forexample, one or more functions of the navigation module 164, controller172, and drive cycle 174 may be performed in a remote location (e.g., ona user's personal device or at a control center) and transmitted to thevehicle 100 during operation.

As described in greater detail below, the heating performance system 160generates a drive cycle profile for operating the vehicle 100 based onthe particular trip, the ambient temperature, and various otherparameters. This drive cycle profile may be implemented by the ECU 108.In some exemplary embodiments, one or more components of the heatingperformance system 160 may be incorporated into the ECU 108 or othervehicle systems. For example, the controller 170 may be part of the ECU108, and/or the user interface 162 may form part of a more general userinterface of the vehicle 100.

The user interface 162 generally functions to enable any type ofinteraction between an operator (or driver) and the heating performancesystem 160, particularly the controller 170 of the heating performancesystem 160. In general, the user interface 162 may include a displaydevice, such as a suitably configured liquid crystal display (LCD),plasma, cathode ray tube (CRT), or head-up display, graphical elements.The user interface 162 enables the user to enter data and/or control thevarious aspects of the heating performance system 160 discussed below.For example, the user interface 162 may be formed by interactivegraphical elements rendered on a touch screen of the display device.Other user input devices may include a keyboard or keypad, a voicerecognition system, a cursor control device, a joystick or knob, or thelike. In further exemplary embodiments, the user interface 162 mayinclude or otherwise interact with a consumer electronic device, such asa smartphone or tablet computer. In some embodiments, the user interface162 may be considered part of the infotainment system that interactswith a command station. In such an embodiment, the user may input thedestination into a first device (e.g., outside of the vehicle on amobile device or personal computer) that is in communication with thecommand station, which in turn, provides the destination and/oradditional related information to the vehicle. In general, and asdescribed below, the user interface 162 enables an operator to inputinformation associated with an intended destination, as well as toenable or disable a heating performance mode.

The navigation module 164 provides navigation information to thecontroller 170, including the current geographical location of thevehicle. In one embodiment, the navigation module 164 is realized as aglobal positioning system (GPS) component that derives the currentposition from real-time GPS data received from GPS satellites. In otherembodiments, the current location may be provided by the user via theuser interface 162. In other embodiments, the current location may bedetermined from non-GPS sources, such as sensor data, or provided fromanother system. The navigation module 164 may additionally receive anintended destination from the operator, e.g., via the user interface162. In some embodiments, the navigation module 164 may infer or derivethe intended destination, e.g. a common trip associated with theoperator.

Based on the current location and the destination, the navigation module164 may generate trip or route information associated with the routebetween the current location and the destination. In particular, thisinformation may include, as examples, the distance, traffic, expectedspeed, stopping points, topography, elevation, weather, and any othersuitable parameter. In some embodiments, the navigation module 164 maygenerate multiple routes between the current location and thedestination. The multiple routes may be presented to the user via theuser interface 162 for selection of the desired trip. In some exemplaryembodiments, the navigation module 164 may assign a probability to eachof multiple routes, and in such embodiments, the user may adjust theprobability of a given route via input on the user interface 162. Assuch, some exemplary embodiments enable customization of the selectedroute, and as a result, the trip information. As described below, thetrip information may be provided to the trip module 172 of thecontroller 170 to generate a trip profile.

The controller 170 generally functions to control operation of theheating performance system 160. The controller 170 may include at leastone processor and/or a memory that may include instructions storedthereon (or in another computer-readable medium) for carrying out theprocesses and methods as described herein. As shown, the controller 170may include a trip module 172 and a drive cycle module 174.

Generally, the trip module 172 is configured to receive the tripinformation from the navigation module 164 and generate a trip profileassociated with the trip. In particular, the trip profile provides anindication or prediction of the energy load associated with tripcharacteristics (e.g., the distance, traffic, expected speed, stoppingpoints, topography, elevation, weather, and the like) as a function ofdiscrete times or distances and/or as cumulative values. As such, anyparameter that impacts the energy load may be considered. In someembodiments, the energy load for a particular intended trip mayadditionally include vehicle parameters such as mass, tire inflation andthe like. The vehicle parameters may be predetermined and/or evaluatedin real time to be considered with respect to the energy load of theintended trip.

In various exemplary embodiments, the energy load may be calculatedbased on a hierarchy of considerations. For example, in one exemplaryembodiment, speed limits and/or reported traffic flow is used togenerate the anticipated energy load. For example, non-optimal speedlimits (e.g., too high or too low) or high traffic density may increasethe anticipated energy load. In this exemplary embodiment, the elevationprofile is then considered. For example, downhill grades will decreasethe energy load while uphill grades will increase the energy load. Asnoted above, additional parameters may be considered. In someembodiments, the anticipated energy load may be updated or adjusted at agiven frequency or period to accommodate changing driving conditions.

Reference is briefly made to FIG. 2, which is an exemplary trip profile200. The trip profile 200 in FIG. 2 depicts dynamometer driving cycles(km/h) on the vertical axis 202 as a function to elapsed time (seconds)on the horizontal axis 204. As shown, the driving profile rises andfalls along the trip based on the various parameters discussed above.For example, the expected energy load of the trip profile 200 initiallyincreases based on the anticipated trip characteristics and then dropsat approximately 140 seconds due to an anticipated stop or coastingsituation. As such, the trip profile 200 provides a continuousprediction of the energy load based on the particular intended trip.Although FIG. 2 depicts dynamometer driving cycles (km/h) as a functionto elapsed time (seconds), the trip profile may take any suitable form.

In some embodiments, the trip module 172 may store previous tripprofiles. Such trip profiles may be associated with common or frequentoperator trips, such as from work to home. In such instances, the tripmodule 172 may retrieve a stored trip profile based on input from theoperator via the user interface 162. In further embodiments, the tripmodule 172 may modify stored trip modules based on trip data from theactual route. In other words, the trip profile may be based on empiricaldata.

The controller 170 further includes a drive cycle module 174. Generally,the drive cycle module 174 generates, selects, or modifies drive cycleprofiles for the ECU 108 to control operation of the actuator assembly120. Such drive cycle profiles are based on the trip profile and otherfunctions discussed below. Generally, the drive cycle profile includes aprediction regarding if and where the engine 132 will operate based onthe battery state of charge, trip profile, outside air temperature, andother parameters, and if the drive cycle profile indicates that theengine 132 will operate, an indication of the timing of operation andnon-operation to meet driver needs for efficiency, heating performance,and the like, as discussed in greater detail below. As such, the drivecycle profiles represent operating commands for the internal combustionengine 132 and the electric motor 134 to meet the anticipated energyload for the trip profile. As noted below, the relative contributionsfor the internal combustion engine 132 and the electric motor 134 mayvary between multiple drive cycle profiles for a single trip profile.Accordingly, in addition to the specific operating commands, each drivecycle profile may include an energy load contribution for the internalcombustion engine 132 and an energy load contribution for the electricmotor 134.

As noted above, typically, the ECU 108 operates the vehicle 100 withelectric power from the battery system 122 via the electric motor 134.However, when the battery system 122 is depleted to a predeterminedlevel, the internal combustion engine 132 is started and the vehicle 100operates with power from the internal combustion engine 132. As aresult, to the extent possible, drive cycle profiles that use theelectric motor 134 instead of the internal combustion engine 132 arefavored, particularly during normal operation. However, whenappropriate, the drive cycle module 174 of the heating performancesystem 160 may command operation according to alternative drive cycleprofiles to improve heating performance, as will be discussed below.

Reference is briefly made to FIG. 3, which is a chart 300 that providesan example of energy usage and an associated drive cycle profile. FIG. 3particularly depicts total energy 310 as a function of time. In FIG. 3,energy is depicted on a first vertical axis 302 and time is depicted onthe horizontal axis 304. With additional reference to the instantaneousor current energy usage in FIG. 2, the total energy 310 in FIG. 3represents the accumulation of that energy usage for a given tripprofile. FIG. 3 additionally depicts the potential energy or energyremaining 320 in the battery system 122, e.g., the remaining charge inthe battery system 122. As noted above, the state of charge of thebattery system 122 may be determined by the battery sensor 154. In FIG.3, battery energy (or charge) is depicted on the second vertical axis306. As expected, the energy remaining 320 decreases as total energy 310increases. The total energy 310 and energy remaining 320 are functionsof the characteristics of the drive profile, and the cycle module 174may determine the total energy 310 and energy remaining 320 based on thetrip profiles provided by the trip module 172.

FIG. 3 additionally depicts a drive cycle profile 330 that, in oneexemplary embodiment, represents a normal or typical operation. Portion332 of drive cycle profile 330 corresponds to propulsion provided solelyby of the electric motor 134, and portion 334 of drive cycle profile 330corresponds to operation of the internal combustion engine 132 (as wellas operation of the electric motor 134, which in most embodiments,operates with the internal combustion engine 132). As shown by drivecycle profile 330, during typical operation, the vehicle 100 operatesonly with the electric motor 134 in portion 332 until the battery system122 reaches a predetermined energy level (e.g. at approximately 1080seconds in the example of FIG. 3). From that point, the vehicle 100additionally operates with the internal combustion engine 132 in portion334 until the end of the trip. As noted above, the drive cycle 330 mayrepresent a typical drive cycle generated by the ECU 108 and/or heatingperformance system 160 to operate the vehicle 100 in which electricenergy is depleted prior to use of internal combustion. As also notedabove, the trip profile may indicate that the trip will end prior todepleting the electric energy relative to result in a profile in whichinternal combustion is not used at all.

In some circumstances, as described in greater detail below, the heatingperformance system 160 may function to modify the typical or defaultdrive cycle to provide improved heating performance by selecting analternate drive cycle profile. This modification may be referred to as aheating performance mode, which may include one or more sub-modes foroperating the actuator system 120 based on various considerations and/orto achieve different results.

Generally, operation of the internal combustion engine 132 provides amore effective source of heat than the PTC heater 142. This isparticularly a concern during cold weather operation with respect tooperator comfort and/or when certain vehicle components may benefit fromheating. In one exemplary embodiment, the heating performance system 160may initiate the heating performance mode to modify the drive cycle toprovide combustion engine operation during times other than at the endof trip profile. FIG. 4 provides an example of one such modification ofdrive cycles.

FIG. 4 is a chart 400 that depicts total energy 410, remaining energy420, and a drive cycle 430 for a trip profile corresponding to the tripprofile of FIG. 2, which also formed the basis of the chart 300 of FIG.3. As such, the total energy 410 is depicted as a function of time withenergy represented on a first vertical axis 402 and time represented onthe horizontal axis 404. FIG. 4 additionally depicts the potentialenergy or energy remaining 420 in the battery system 122, e.g., theremaining charge in the battery system 122, with energy remainingrepresented on the second vertical axis 406.

FIG. 4 also depicts an exemplary drive cycle profile 430 as generated ormodified by the heating performance system 160 during a heatingperformance mode. Portion 432 of drive cycle profile 430 corresponds topropulsion provided solely by the electric motor 134, and portion 434 ofdrive cycle profile 430 corresponds to operation of the internalcombustion engine 132. As shown by drive cycle profile 430, the portion434 corresponding to combustion engine operation occurs at the beginningof the drive cycle profile 430 (e.g., from 0 seconds to approximately370 seconds), and the portion 432 corresponding only to electric motoroperation occurs at the end of the drive cycle profile 430 (e.g., from370 seconds to the conclusion of the drive cycle profile 430). As shown,the energy remaining 420 is relatively constant during portion 434 dueto operation of the engine 132, and the energy remaining 420 decreasesduring portion 432 because the electric motor 134 is operating forpropulsion.

The total energy 410 corresponds to the total energy 310 of FIG. 3 sincethe trip profile is identical. Moreover, even though the drive cycleprofile 430 in FIG. 4 has been modified relative to the drive cycleprofile 330 in FIG. 3, the percentage of time that the drive cycleoperates with the internal combustion engine 134 (e.g., the respectiveenergy load contribution) is approximately the same. This indicates thatthe electric motor (and the battery system 122) and the internalcombustion engine 132 make approximately the same energy contributionsfor the trip profile in each of the respective drive cycles. As aresult, the same amount of desired electric operation is maintained.However, since the heat from the internal combustion engine 132 may nowbe used earlier in the trip profile, heating performance is improved. Inother words, the operator may be more comfortable over the entire tripas a result of the improved heating provided by the internal combustionengine 132. In effect, the heating performance mode enables the user tobenefit from the improved heating performance that is a by-product ofinternal combustion engine operation by utilizing the internalcombustion engine 134 earlier within the trip. Additionally or as analternative, the earlier availability of the heat from the internalcombustion engine 132 may be used to advantageously raise thetemperature of certain engine components, such as the transmission. As acomparison, in the drive cycle profile 330 of FIG. 3, the internalcombustion engine 132 does not operate until the end of the tripprofile, thereby resulting in effective heating of the vehicle 100 onlyat the end of the trip profile. Upon generation of the modified drivecycle profile, the controller 170 may provide the modified drive cycleprofile to the ECU 108 for implementation. Scenarios for generating orselecting the heating performance mode will be described below.

Now that the structure of the heating performance system 160 has beendescribed, an exemplary description of operation will be provided as amethod 500, which is depicted as a flowchart in FIG. 5. Method 500functions to improve heating performance in a vehicle, particularly aplug-in, hybrid, or extended range vehicle. In one exemplary embodiment,the method 500 may be implemented with the vehicle 100 discussed above.As such, FIG. 1 will be referenced in the discussion of FIG. 5 below.

In a first step 510, the heating performance system 160 (e.g., thecontroller 170) evaluates whether or not the driver has enabled theheating performance mode. The heating performance mode may be initiatedby the operator via the user interface 162 and/or automatically. If theheating performance mode is not enabled, the heating performance system160 returns to the start of the method 500 and continues to evaluate theenablement of the heating performance mode. If the heating performancemode is enabled, the heating performance system 160 continues to step520.

In a second step 520, the heating performance system 160 (e.g., thecontroller 170) evaluates the ambient temperature. The temperature maybe determined, for example, with the ambient sensor 150. Generally, theheating performance system 160 determines if the ambient temperature issuitable for heating and/or if the PTC heater 142 will be sufficient toheat the vehicle. As such, in the second step 520, the heatingperformance system 160 determines whether or not the temperature isbetween a predetermined low temperature and a predetermined hightemperature. In one exemplary embodiment, the high temperature may beselected based on a number of factors, including a selection by themanufacturer, a selection by the operator (e.g., via user interface142), operational parameters, regulatory, and/or environmental factors.Generally, the high temperature represents the temperature above whichenhanced heating performance is no longer needed or desired (e.g., whenheating is not necessary and/or the PTC heater 142 is sufficient).Typically, the predetermined low temperature is selected based onregulation and/or a function of the capabilities of the PTC heater 142to operate at particularly low temperatures. Below the predeterminedtemperature, operation of the engine 132 is typically necessary tooperate one or more vehicle functions, such as windshield defrosting.Accordingly, if the temperature is outside of the range in step 520, themethod 500 returns to the start of the method 500. If the temperature iswithin of the range in step 520, the method 500 proceeds to step 530.

In a third step 530, the heating performance system 160 (e.g., thecontroller 170) determines if other compliance criteria are applicableand acceptable. As an example, a determination or evaluation regardingthe fidelity of the GPS of the navigation module 164 may be considered.Generally, GPS provides an estimate of the accuracy of theconstellations in their current configuration, which allows for thecontroller 170 (or other system) to predict an error surrounding a givenposition in real time. However, certain algorithms that require highprecision may be disabled if a certain level of accuracy is not met. Insuch instances, and because the heating performance system 160 is makinglarge quantitative energy assessments across a drive cycle, suchcompliance criteria may not be very stringent. Additionally, there aretimes when GPS data becomes temporarily inaccurate or unavailable.During these periods, the system 160 uses on board sensor data (wheelspeeds/steering angle data) to “project” the location in space (e.g.,“dead reckoning” technique). However, in some instances, if thesesensors are unavailable, operation of the heating performance system 160may be disabled. Any suitable compliance criteria may be selected, andin some embodiments, such compliance criteria may be incorporated into avehicle health system and/or omitted. If the compliance criteria areunacceptable, the method 500 returns to the start of the method 500. Ifthe compliance criteria are acceptable, the method 500 proceeds to step540.

In a fourth step 540, the heating performance system 160 (e.g., thecontroller 170) evaluates the trip and generates a trip profile. Asnoted above, the trip profile may predict the energy usage associatedwith a trip between a current location and a selected destination.

In a fifth step 550, the heating performance system 160 (e.g., thecontroller 170) determines whether or not the energy usage or loadassociated with the trip profile is greater than the charge range of thevehicle. If the load is not greater than the charge range of thevehicle, then the method 500 exits the heating performance mode andreturns to the start of the method. Generally, if the load is notgreater than the charge range, it indicates that the internal combustionengine operation will not be necessary, and therefore, unavailable toshift within the drive cycle profile. If the load is greater than thecharge range of the vehicle, the method 500 proceeds to step 560.Additionally or alternately, in the fifth step 550, the heatingperformance system 160 may further consider the energy load needed toheat coolant to a temperature such that the total energy expended withinthe heating performance mode is approximately equal for the designatedtrip profile to the energy without the heating performance mode. If theenergy load is greater, the heating performance mode is consideredworthwhile and initiated by proceeding to step 560.

In a sixth step 560, the heating performance system 160 (e.g.,controller 170) determines the operational sub-mode. The determinationin step 560 to determine the operational sub-mode may be based on anumber of factors. In one exemplary embodiment, this step 560 may beomitted such that the method 500 proceeds directly to step 570 tooperate in engine-on sub-mode. However, other factors may be consideredto operate in an alternate sub-mode 570, which may encompass a number ofdifferent types of operation, as described below.

In one exemplary embodiment, the heating performance system 160determines the operational sub-mode by comparing the warming energyrequired to warm the vehicle to the anticipated engine energy associatedwith the trip profile (“anticipated engine energy”). If the warmingenergy is not substantially greater than the anticipated engine energy,then the method 500 proceeds to step 570 in an engine-on sub-mode. Ifthe warming energy is substantially greater than the anticipated engineenergy, then the method 500 may proceed to step 580 in the alternatesub-mode. In one exemplary embodiment, the warming energy may beapproximately 25% greater than the anticipated engine energy to proceedto step 580 in the alternate sub-mode. Additional considerations in step560 may be the charge of the battery system 122, length of the trip, andother optimization systems or techniques. More specific examples areprovided below.

Referring to step 570, the heating performance system 160 (e.g.,controller 170) initiates the engine-on sub-mode. In step 570, theengine 132 is operated in order to propel the vehicle, generally at thebeginning of the trip, such as shown in the drive cycle profile 430 ofFIG. 4. As noted above, the engine operation in step 570 generallycorresponds to the engine operation that would otherwise be conducted atthe end of the trip profile. As noted above, engine operation in step570 generally occurs at the beginning of the trip such that the heatenergy may be used in the passenger compartment as soon as possible.However, in some embodiments, it may be determined that the timing ofengine operation may be more effective at a point other than thebeginning of the drive cycle, such as during the middle or intermediateportions of the trip profile. This determination may be based on anumber of factors, including passenger comfort, passenger selection,trip profile, anticipated energy usage, and other system optimizationprograms.

In step 572, the heating performance system 160 (e.g., controller 170)determines if the engine has reached a predetermined target temperature.The predetermined target temperature may be based on a number offactors, including customer comfort, operational performance, and fuelefficiency. If the engine temperature is less than the targettemperature, the method 500 continues to evaluate the temperature instep 572. If the engine temperature is greater than or equal to thetarget temperature, the method 500 restarts, effectively exiting thewarming operation of the sub-mode. Other parameters, such as acomparison in nominal engine load and modified engine load, may also beconsidered to exit or restart the method 500. As a result of thisoperation, approximately the same amount (or less) fuel is used ascompared to if the engine had started at the end of the drive cycle.Moreover, the driver and passengers enjoy the benefit of the moreeffective heating performance resulting from operation of the engine 132earlier in the trip, thereby also enabling the enjoyment and use of theresidual heat in the passenger compartment throughout the trip, evenafter the engine 132 is no longer operating.

Referring to step 580, the heating performance system 160 (e.g.,controller 170) initiates the alternate sub-mode. In this sub-mode, thedrive cycle profile may modify the timing of the engine 132 to aposition other than the end of the trip, similar to sub-mode of step570. However, the engine operation may be more limited or delayed toincrease the temperature of the passenger compartment to a more limitedextent such that some heating assistance is provided, even if thewarming energy to completely or more thoroughly warm the passengercompartment is too much of an energy cost. In one embodiment of thealternate sub-mode, the engine 132 operates only to a level to sustainthe charge of the battery 122, and thus, provide some amount of heatassistance. Such operation of the engine 132 may occur at the beginningof the trip or during an intermediate portion of the trip. As describedbelow, the alternate sub-mode of step 580 may be initiated to utilizethe heat energy of the engine 132 for additional or other purposes.

In one exemplary embodiment of the alternate sub-mode of step 580, thetiming of operation of the engine 132 may be modified or adjusted basedon operation or capability of the PTC heater 142, charge of the batterysystem 122, and the trip profile. For example, if the heatingperformance system 160 determines that the capability of the battery toaccept charge is poor (e.g. because of temperature or current charge),the system 160 may delay the initiation of the engine 132 (e.g., ascompared to the engine-on sub-mode) and operate the PTC heater 142 toassist heating of the passenger compartment, as well as provide power toother systems of the vehicle. For example, as compared to operationdepicted in FIG. 4, this embodiment of the sub-mode would offset theengine start time by a predetermined time to optimize or improve energyusage.

In a further embodiment of the alternate sub-mode, the length of thetrip may be considered. For example, for shorter trips, the heatresulting from engine operation may be diverted to component heating,such as transmission heating. In some situations, the component heatingmay be initiated based on the needed and/or conditions of thecomponents, e.g., when it would be particularly advantageous toprioritize heat energy to the transmission or certain types of vehiclefluids.

In step 582, the heating performance system 160 (e.g., controller 170)determines if the engine has reached a predetermined target temperatureand/or whether another operating parameter has been reached. Thepredetermined target temperature may be based on a number of factors,including customer comfort and operational performance. If the enginetemperature is less than the target temperature, the method 500continues to evaluate the temperature in step 582. If the enginetemperature is greater than or equal to the target temperature, themethod 500 restarts, effectively exiting the warming operation of thesub-mode. In some embodiments, the one or more of the sub-modes in steps570, 580 may be omitted.

In one exemplary embodiment, the method 500 is performed once atignition or the beginning of a trip. In another embodiment, the method500 may be performed iteratively, at predetermined intervals or timeperiods. In further embodiments, the method 500 may be performedcontinuously such that the above-referenced steps are continuouslyconsidered and executed as discussed above.

Accordingly, improved heating performance is provided. Particularly,heat from internal combustion may be used earlier in a trip to provideimproved operator comfort or component warming. Even though heatingperformance is improved, operation may be controlled to result in thesame relative contributions of energy usage of the internal combustionengine and the electric motor.

While at least one exemplary embodiment has been presented in theforegoing detailed description of the invention, it should beappreciated that a vast number of variations exist. It should also beappreciated that the exemplary embodiment or exemplary embodiments areonly examples, and are not intended to limit the scope, applicability,or configuration of the invention in any way. Rather, the foregoingdetailed description will provide those skilled in the art with aconvenient road map for implementing an exemplary embodiment of theinvention. It being understood that various changes may be made in thefunction and arrangement of elements described in an exemplaryembodiment without departing from the scope of the invention as setforth in the appended claims.

What is claimed is:
 1. A system for a vehicle, comprising: a batterysystem; an electric motor coupled to the battery system and configuredto selectively provide power to the vehicle with energy from the batterysystem; an internal combustion engine configured to selectively providepower to the vehicle; a heating system configured to transfer heat fromthe internal combustion engine to a passenger compartment of thevehicle; an ambient temperature sensor configured to determine anambient temperature; and a controller configured to receive the ambienttemperature from the ambient temperature sensor and to operate theelectric motor and the internal combustion engine according to one of aplurality of drive cycle profiles, the controller configured to selectthe drive cycle profile from the plurality of drive cycle profiles basedon the ambient temperature, the plurality of drive cycle profilesincluding: a first drive cycle profile that commands power from theelectric motor until the battery system reaches a predetermined state ofcharge and subsequently commands power from the internal combustionengine, and a second drive cycle profile that commands power from theinternal combustion engine and subsequently commands power from theelectric motor, wherein the controller is configured to select the firstdrive cycle profile when the ambient temperature is greater than thepredetermined temperature and to select the second drive cycle profilewhen the ambient temperature is less than or equal to the predeterminedtemperature.
 2. The system of claim 1, wherein the second drive cycleprofile commands power from the internal combustion engine at abeginning of the second drive cycle profile.
 3. The system of claim 1,wherein the controller is configured to receive a current location andan intended destination and to generate a trip profile based on thecurrent location and the intended destination.
 4. The system of claim 3,wherein the second drive cycle profile commands power from the internalcombustion engine and subsequently commands power from the electricmotor such that the battery system reaches an estimate of thepredetermined state of charge at the intended destination.
 5. The systemof claim 4, wherein the plurality of drive cycles further includes athird drive cycle profile that commands power only from the electricmotor, the controller configured to select the third drive cycle profilewhen the vehicle is predicted to reach the intended destination prior tothe battery system reaching the predetermined state of charge.
 6. Thesystem of claim 3, wherein the first drive cycle profile defines a firstinternal combustion engine energy load contribution and a first electricmotor energy load contribution for the trip profile and the second drivecycle profile defines a second internal combustion engine energy loadcontribution and a second electric motor energy load contribution forthe trip profile, and wherein the first internal combustion engineenergy load contribution is approximately equal to the second internalcombustion engine energy load contribution.
 7. The system of claim 1,wherein the controller is configured to receive an initial location andan intended destination and to generate a trip profile for a tripbetween the initial location and the intended destination, and whereinthe controller is configured to select between the first drive cycleprofile and the second drive cycle profile upon initiation of the trip.8. The system of claim 7, wherein, during the trip, the controller isconfigured to receive a current location and to update the trip profilebetween the current location and the intended destination, and whereinthe controller is configured to reselect between the first drive cycleprofile and the second drive cycle profile based on the updated tripprofile.
 9. The system of claim 8, wherein, during the trip and whenoperating in accordance with the second drive cycle profile, thecontroller is configured to receive the ambient temperature at thecurrent location and to switch to the first drive cycle profile when theambient temperature is higher than the predetermined temperature. 10.The system of claim 8, wherein the predetermined temperature is a firstpredetermined temperature and wherein, during the trip and whenoperating in accordance with the second drive cycle profile, thecontroller is configured to receive an engine operating temperature andto switch to the first drive cycle profile when the engine operatingtemperature is higher than a second predetermined temperature.
 11. Amethod for operating a vehicle with an electric motor that providespower to the vehicle with energy from the battery system, an internalcombustion engine, and a heating system that transfers heat from theinternal combustion engine to a passenger compartment of the vehicle,the method comprising the steps of: receiving an initial location and anintended destination; generating a trip profile for a trip between theinitial location and the intended destination; determining, with anambient temperature sensor on the vehicle, an ambient temperaturereceiving, by a controller on the vehicle, the ambient temperature;selecting, by the controller on the vehicle, a drive cycle profile froma plurality of drive cycle profiles based on the trip profile and theambient temperature, wherein the plurality of drive cycle profilesincludes a first drive cycle profile and a second drive cycle profile,wherein the first drive cycle profile commands power from the electricmotor until the battery system reaches a predetermined state of chargeand subsequently commands power from the internal combustion engine, andwherein the second drive cycle profile commands power from the internalcombustion engine and subsequently commands power from the electricmotor, wherein the selecting step includes selecting the first drivecycle profile when the ambient temperature is greater than apredetermined temperature and selecting the second drive cycle profilewhen the ambient temperature is less than or equal to the predeterminedtemperature; and operating the vehicle according to the selected drivecycle profile.
 12. The method of claim 11, further comprising the stepof generating the first drive cycle profile and the second drive cycleprofile for operating the vehicle according to the trip profile, whereinthe second drive cycle profile commands power from the internalcombustion engine and subsequently commands power from the electricmotor such that the battery system reaches an estimate of thepredetermined state of charge at the intended destination.
 13. Themethod of claim 11, wherein the plurality of drive cycles furtherincludes a third drive cycle profile that commands power only from theelectric motor, and wherein the selecting step includes selecting thethird drive cycle profile when the vehicle is predicted to reach theintended destination prior to the battery system reaching thepredetermined state of charge.
 14. The method of claim 11, wherein thefirst drive cycle profile defines a first internal combustion engineenergy load contribution and a first electric motor energy loadcontribution for the trip profile and the second drive cycle profiledefines a second internal combustion engine energy load contribution anda second electric motor energy load contribution for the trip profile,and wherein the method further comprises generating the first drivecycle profile and second drive cycle profile such that the firstinternal combustion engine energy load contribution is approximatelyequal to the second internal combustion engine energy load contribution.15. The method of claim 11, further comprising receiving, during thetrip, a current location; generating an updated trip profile between thecurrent location and the intended destination, and selecting an updateddrive cycle profile from the plurality of drive cycle profiles based onthe updated trip profile.
 16. The method of claim 15, wherein the stepof receiving the ambient temperature includes receiving an updatedambient temperature at the current location, and wherein the step ofselecting the updated drive cycle profile includes selecting the firstdrive cycle profile when the updated ambient temperature is higher thanthe predetermined temperature.
 17. The method of claim 15, wherein thepredetermined temperature is a first predetermined temperature, andwherein the method further comprises receiving an engine operatingtemperature, and wherein the step of selecting the updated drive cycleprofile includes selecting the first drive cycle profile when the engineoperating temperature is higher than a second predetermined temperature.18. A heating performance system for a vehicle with an electric motorand an internal combustion engine, the heating performance systemcomprising: a trip module configured to generate a trip profile for atrip between an initial location and an intended destination; a drivecycle module coupled to the trip module and configured to generate atleast a first drive cycle profile and a second drive cycle profile basedon the trip profile, wherein the first drive cycle profile commandspropulsion power from the internal combustion engine at a first positionduring the trip profile and the second drive cycle profile commandspropulsion power from the internal combustion engine at a secondposition during the trip profile, earlier than the first position; anambient temperature sensor configured to determine an ambienttemperature; and a controller coupled to the drive cycle module and theambient temperature sensor and configured to select between the firstdrive cycle profile and the second drive cycle profile based on theambient temperature for operation of the vehicle according to theselected drive cycle profile, wherein the controller is configured toselect the second drive cycle profile when the ambient temperature isless than a predetermined temperature such that heat from the internalcombustion engine is directed into a passenger compartment of thevehicle earlier in the trip profile.